1. Technical Field
Various embodiments of the present invention relate to an internal temperature measuring device and the like.
2. Related Art
An internal body temperature and base metabolism are bio-information related to a person. The internal body temperature denotes a temperature of a place deeper (inside) than the skin surface of the human body, regardless of the site of the human body.
As technologies of measuring an internal body temperature, for example, a technology in which a probe internally housing a heater is mounted on the surface of a living body, heat is applied from the heater, and the internal temperature is computed by measuring the temperature when the heat flow radiated from a living body becomes “0” (for example, refer to JP-A-2002-202205), a technology in which an internal temperature is measured by substituting heat conduction inside a living body by an equivalent circuit, that is, an electric circuit (for example, refer to JP-A-2014-052350), and the like are known. Moreover, an instrument of measuring an internal body temperature by inserting a device into the external auditory meatus is known (for example, refer to JP-A-2011-072637).
As a technology of measuring base metabolism, a technology in which an instrument equipped with a heat flow thermistor for measuring a heat flux, and a plurality of temperature sensors is attached to an arm or the like of a measurement target person, and the base metabolism is obtained based on the heat flux and the temperature difference is known (for example, refer to JP-A-2011-120917).
In order to continuously and precisely measure bio-information of a person, particularly bio-information related to a temperature such as an internal body temperature and base metabolism for a long time (for example, one day or longer), it is important to find a way to minimize the influence of various types of errors.
From the view of convenience and comfort of measurement, in an instrument having the form disclosed in JP-A-2011-072637, a device has to be inserted into the external auditory meatus and to be kept therein, and it is difficult to mention that the device is preferable. An instrument having the form disclosed in JP-A-2011-120917 may be preferable.
However, in the technology disclosed in JP-A-2011-120917, the influence of an error caused due to the shape of a measurement target site and an error caused due to biasing of a heat source position inside a living body is not taken into consideration. In other words, generally, in an arm and the like of a living body, the position of the heat source is often biased from the center. For example, in a wrist, a surface temperature and a heat flow are characterized to vary due to the difference of the position of a site between the front and the back, that is, the back side and the palm side. In JP-A-2011-120917, since measurement errors caused due to the difference of the position of a measurement site between the front and the back are not compensated for, the measurement errors caused due to the difference of the position of the measurement site between the front and the back are included.
On the other hand, in a case where the technology of JP-A-2002-202205 is applied to an instrument having the form of JP-A-2011-120917, since the technology of JP-A-2002-202205 requires a heater, it is difficult to realize an instrument having a favorably convenient and comfort size. Since a heater is required, there are disadvantages such as whether to continue driving the heater, whether to intermittently drive the heater, and how to ensure a power source during measurement taken for a long period of time.
Moreover, in a case where the technology of JP-A-2014-052350 requiring no heater is applied, the influence of an error caused due to biasing of the heat source position inside a living body is included. In other words, actually, the inside of a living body is naturally a heat conductive system including heat generation caused due to metabolism of tissue and a heat inflow from blood to the tissue, and the heat flow varies depending on the depth inside the living body.
The above-described disadvantages are not limited to measuring an internal temperature of a person and are similarly applied to measuring an internal temperature of a different animal. The same circumstances are applied to analyzing an internal temperature of a semiconductor chip such as large scale integration (LSI), and analyzing an internal temperature of a machine component or a structure body internally having a heat source.